A well-known guest is murdered at a party for social-media influencers. Serena and Folsom investigate the brutal killing. Back at the lab, Allie, on her day off, and Chris look for cold cases that may link to their current string of connected murders. Maxine pulls away Chris at Josh's request. That's because of Chris's side hustle posting about CSI life. The killer wrote Chris's Twitter handle in invisible ink on the victim's face. Max puts Chris in charge of the investigation. Chris thinks it's a revenge killing, explaining that Nate had been accused of killing his neighbor with an axe four years ago. Chris posted a video about the case that went viral and helped lead to an acquittal. Nate's housemate Warren immediately asks for a lawyer. There's no trace of the killer at the crime scene. Warren's sweat was on the murder axe. Testing proves the axe wasn't the murder weapon. Chris says Warren was being framed. Max worries that Chris could be in danger and she wants him to carry a gun. Chris determines that a drone was the murder weapon. Chris and Serena find a drone at Murder House, but it was used in the original murder by Warren four years before. Chris blames himself for getting Warren off. Chris is receiving death threats. Serena checks in on Max's recovery. Chris and Folsom find the remains of a bloody wipe near where the murder drone went down. Josh's arms were all scratched up retrieving the sample and Chris finds similar scratches on Vincent's arms. Vincent also has pink eye, just like Nate did. Vincent was rejected twice for his dream job: CSI. So he was jealous of Chris's success. Chris admits online that he was wrong about the earlier murder, then he signs off social media for good.